The SheldonLeslie Experiment
by Mislav
Summary: Set post the episode "The Hamburger Postulate". Sheldon thinks that his suffering is over, but later that night, Leslie causes him another "problem"-and she is the only one who can take care of it. Smut.


**A/N: I don't own any of the Big BangTheory characters and I am not making any money from writing this.**

**Please forgive any minor spelling or grammar mistakes, English is not my native language.**

**This story takes place post the episode "The Hamburger Postulate". This is just a oneshot.**

Sheldon was lying in bed, frustrated and unable to sleep.

All because of that woman... Leslie... Leslie Winkle.

Not only did she correc... tempered with his equations, like that isn't frustrating enough, she was also so loud that morning that he couldn't stop thinking about what she did... what she did with Leonard. Over and over again.

Never before did he witness to that sort of situation-except when he caused Joyce Kim to run out of the Leonard's bedroom, but that time they weren't actually having sex. Now, he couldn't stop thinking about what Leslie did with Leonard that morning... and last night.

She seemed to enjoy that a lot... like nothing else matters at that point. Sheldon always thought that coitus is something dirty and primitive, something that shouldn't be done for any other purposes except for reproduction, something that takes human mind away from more important things. He did have certain... urges. Ever since he was a teenager. But he never acted upon them. He never had sex, he never masturbated. Whenever he would feel an urge to do so, he would remind himself what dirty and messy result would acting upon those urges have and soon, those urges would disappear.

But now... it was different. It was eleven pm and he had no new projects to work on. Thinking about his older projects would only remind him on what Leslie did with his equations, resulting in more and more frustration. And he recently got another problem... the one that was tenting his pajama bottoms. He simply couldn't get the mental images of Leslie's naked body reveling in pleasure out of his mind. Feeling of arousal was evident, but what was bothering him more were feelings of confusion and frustration.

He sighed and glared at his alarm clock. It was almost twelve pm.

No, he decided, he isn't going to get Leslie get off the hook. He isn't going to suffer alone. She caused that problem, she better take care of it herself. His free time-or, in this case, sleeping schedule-was too precious for him to waste like that, not to mention that mental image of him pleasuring himself and act upon the basic urges like an animal was causing him sickness.

#

Leslie was sitting on the couch in her living room, reading a book. The lights were on.

She felt a little bit guilty due to a way she broke up with Leonard. He was a nice guy after all, and he only wanted the best for both of them. But it was better that way: at least he knew what to expect from her. She hated to admit it, but she couldn't control her feelings, or in this case, the lack of certain ones.

It was close to one am and she was just planning to go to bed, when somebody rang the doorbell. Surprised, she closed the book and put it on the coffee table, then walked toward the door and opened them, too distracted to bother to look through the peephole.

She immediately regretted that, as soon as she saw who was standing in front of her front door. Sheldon Lee Cooper. Or Dr. Dumbass, to be exact.

She was shocked, frustrated and confused in the same time. Hundreds of questions went through her mind. What was he doing here? What did he want? Why was he here? What should she do? Upcoming feelings and thoughts were so powerful and confusing that she just remained silent for the next few second, staring at him eyes wide. Sheldon shivered as soon as he saw her, heat rushing through his body due to a reminder of what she did with Leonard. His cock was hard, but was constricted in his jeans.

"Leslie", Sheldon said, obviously trying to start a conversation. That was enough for Leslie to snap out of her confusion. His voice was strange: he didn't sound arrogant or indifferent, he sounded more like... someone who is confused or even ashamed. Still, she didn't think that he came to her place to apologize to her.

"Dumbass", she replied, looking at him with a single raised eyebrow. She couldn't help but smirk when she noticed how he had blushed at her remark, obviously knowing that nothing he could think of saying at that moment, no matter how smart it may sound, wouldn't make her feel that he is smarter than her or put her down.

"OK, enough of the chit-chat", he quickly replied, and Leslie smirked again, due to his desperate attempt to keep his cool. Then he raised his head and looked her in the eyes. "May I come in, please?", he asked.

"Uhm... OK." That was the only thing she managed to say, because that whole situation seemed to be getting more and more confusing. She hoped that he would say what he has to say and leave, if only she obeys.

Sheldon walked over to the couch, ran his hands down his thighs and bit his lower lip before he turned facing Leslie and looking her in the eyes.

"OK, I'll be honest with you", he said. "I heard you and Leonard this morning while you were... engaging in coitus. And now... I have problems. A problem, to be exact."

Leslie put crossed arms over her chest, glaring at him.

"We were two completely consensual adults."

"Never the less, your actions caused my problem and I expect you to take care of it."

"What problem?"

Nothing, absolutely nothing could prepare Leslie for what happened next. Sheldon pulled down his jeans down to his ankles. He was wearing white briefs, huge and very visible bulge tenting the middle of it. She nearly screamed and jumped aside, looking away, her cheeks flushed red.

"W... what... what the heck?"

"You asked me "what problem". Well... this is the problem", he said, gesturing toward his bulge.

Leslie couldn't believe her ears.

"Uh... you... can't you take care of it yourself?"

Sheldon looked at her like she was crazy.  
>Leslie frowned.<br>"You know... masturbate?"

"Leslie... for years, I watched brilliant people being distracted, put down or even ruined because they couldn't control their basic urges. I can control them, I just need to get rid of... this", he said, blushing a little as he pointeed at his bulge. "Anyway, since I was able not to act upon my basic urges for over a decade, I am not planning to act upon them now. Also, my free time and energy is too precious to be waisted like that."

"And mine isn't?", Leslie asked, feeling herself getting calmer and returning to her usual, snarky self.

"Even if it were", Sheldon said, doing his best to avoid conflict in such a delicate situation, "you caused it, you take care of it."

"I was with Leonard, so he is partially responsible too. Did you ask him first to, you know, do you a favor?", Leslie asked, trying not to giggle.

"I have urges, no matter how much I hate it to admit. I keep my urges under control, but by doing so I also learned that I am heterosexual", Sheldon explained, completely unaware of the gay joke that Leslie just said. "Also, Leonard is my roommate, so having him take care of my problem would bring us lots of awkward situations in the future-at least that's my understanding of a social protocol. Also, while watching Leonard acting upon his basic urges over the years, I came to conclusion that he is heterosexual too-he even stated that himself few times. Therefore, he wouldn't agree to do such a thing. And, from what you did with Leonard last night and this morning, it is safe to conclude that you are heterosexual too-or at least bisexual. You are the only logical option."

Leslie smirked and glared at him once again. "But, if you are heterosexual, that means that you are attracted to me... right?" She didn't know was the idea of Sheldon being attracted to her turning her on, amusing her, or just making her laugh, but whatever it was, she liked it.

Sheldon blushed and looked down at the floor. "That's irrelevant. Will you help me get rid of this problem or not? By the way, if you try to hurt me, I will call the police."

She slid her hands off her chest and smiled.

"Just go to my room", she smiled and lead him to her room. He was moving slowly, due to the jeans being pulled down to his ankles, but he made it to the bed. Bed sheets looked clean enough for him, he sat down on the bed. Leslie walked in front of him, put her hands on her hips and looked at him, looked down at him-at his bulge.

"Take it off", she said, her voice making Sheldon shiver. He wasn't sure what did she mean by that, but he had some sort of idea, so he slowly removed his shoes, socks, jeans and briefs and put them on the bed. He decided not to take off the rest off his clothes unless Leslie says him so, because he still wasn't completely comfortable with being naked around her. Lust sparkled in Leslie's eyes once she saw his rock hard, ten inch long cock. Sheldon took a bottle of Purell out of right pocket of his jeans and handled it to her. Leslie rolled her eyes, but took it and started applying it on her hands.

"There is only one way that I can get rid of your problem, and it involves something sexual."

The terror was evident on Sheldon's face. "Oh, no...", he whispered, staring at her blankly.

"Would you like to do it yourself?"

"Of course not!", Sheldon almost jumped off the bed, completely terrified by the idea.

"You see? It is not going to be too bad."

Sheldon sighed, wanting to get that over it as soon as possible. He picked up few wet wipes from the package on the bedside table, then put few of them on his crotch and groin area. Leslie barely kept herself from laughing, but she managed to stay cool. She finished applying Purell on her hands and put the bottle on the bedside table, then sat on the bed next to Sheldon and got on work.

When she wrapped her fingers around his rock hard length, she shivered and felt a warm jolt going right down to her pussy. Sheldon moaned, suddenly feeling nice, tingly feeling going down his back. It was weird, something that he had never experienced before. He didn't know should he like it or hate it. In the same time, it felt nice and wrong, pleasant and confusing.

Leslie started hand-jobbing him, pulling his foreskin back and forth. Sheldon laid down on the bed, breathing heavily. Leslie's actions were overwhelming to his senses: he would feel a pleasure in every part of his body and that feeling would only increase as she would go on. There was still an amount of fear and discomfort present, but it was only fading away more as the time was going by.

Leslie was very confused. She had sex with Leonard multiple times last night and usually, that would hold her for months, but now, she was more turned on than ever. Her clit was rock hard, occasionally brushing against her panties as her body was moving followed by her actions, providing her a little release but in the same time she was feeling a desperate need for more. Sure, Sheldon was well endowed and they were engaged in something sexual, but to be aroused by him... man that she despised? Although... she couldn't help but find the idea of her having such a powerful influence on him, who was always puting down her and her work, to be quite... satisfying, to say at least. Maybe that was a part of a reason too? She was never into dominance during sex and all that kinky stuff, but she concluded that could very well be the reason.

Deciding that she can't take it anymore, she slipped a finger down her jeans and trailed it down to her panties and then underneath, to her pussy, her arousal increasing every time when her finger would move closer to her heated, pre-cum creamed womanhood. She didn't want dr. Dumbass to know that she was aroused by him, but since he was lying down on his back on the bed, obviously not paying attention to her, she decided to surrender to temptation. As she slipped her finger inside, she felt warm pleasant shivers massaging every inch of her body while her vagina muscles rubbed against her finger. She let out a rather loud moan, frowning immediately afterward-luckily, Sheldon obviously didn't pay attention to that. Soon, her finger brushed against her clit, and she immediately felt the same thing that she felt few seconds before, only thousand times better. She was barely able to keep herself from screaming: she bit her lower lip so hard that she almost drew blood and started hand jobbing Sheldon harder and faster than ever, her lust-clouded eyes centered on his crotch, images of his cock in her mouth and pussy filling her mind, his moaning only adding to her arousal, feeling of his pre cum dripping on her fingers sending jolts right down her crotch with every drop.

Soon, Sheldon felt strong albelt pleasant pressure in his balls: then that same pressure moved up his cock. In the next moment, he felt like the series of oscilating waves of pleasure ripped through his body and he came, his warm, wet cum dripping on Leslie's fingers, causing her clit to harden even more and press hard against her warm, constantly moving finger while in the same time rubbing against her G-spot. While he was coming, all that feelings returned, stronger than ever, but after few seconds everything was over and osciliating waves of pleasure got replaced by a wonderful feeling of relaxation in all of his limbs and tingly warmth spreading in lower part of his stomach and between his thighs. Almost immediately afterward, Leslie came too, feeling shivers spreading through every single part of her body while hot sweat was rolling down her back, her hand still on Sheldon's now soft but still hot cock; she cried out in ecstasy, her warm wet cum rolling down her finger and creaming her panties, her clit pulsing uncontrollably and rubbing against her G-spot as her juices washed over it.

Slowly, she opened her eyes and moved her hand off Sheldon's cock, then looked at it. Sheldon was still lying down on the bed, breathing heavily. His warm cum was centered on her fingers, and her mouth watered as she felt a sudden thirst for it. She wrapped her lips around her finger, licking every drop of his cum before swallowing it, slowly, savoring every feel and taste. As soon as she felt Sheldon's warm cum rolling down her throat and shivered due to it's bittersweet taste, she felt an irresistible desire for more, and soon enough, she was licking and sucking on her fingers aggressively, feeling it's warmth and taste more clearly by doing so while her feelings of lust and pleasure kept increasing with every second.

"What are you doing?"

Leslie frowned upon hearing Sheldon's voice. She slowly opened her eyes while pulling her fingers out of her mouth and saw him sitting up on the bed, looking at her, obviously confused.

"Uhm... nothing", she replied, feeling herself blushing as she licked the last drop of his cum off her lower lip. Sheldon just shrugged and carefully picked wet wipes off his crotch and groin area and threw them into a near by trash can, seemingly satisfied by the fact that most of the cum landed on them. He picked up few more wipes and used them to wipe his cock and balls clean before threwing them in the trash can as well. But, due to a friction, he soon turned hard again.

"Oh, great!", he groaned. "Now we need to do that all over again." Leslie's face turned dark, idea appearing in her mind.

"Actually, Sheldon, I think that I know even more efficient way to get rid of your problem. Are you willing to try it?"

"Anything, as long as I get rid of this!"

"OK. Just follow me." Leslie quickly took off her jeans and T-shirt and put those articles of clothing on the chair near by. Sheldon followed by and took of his T-shirt, putting it on the bed. Leslie felt a heat rushing through her body as she saw his naked torso, his surprisingly muscular shoulders and flat stomach. She removed her bra and panties, throwing them on the floor. Sheldon licked his dry lips, looking at her naked body in mixture of lust and fascination, feeling his cock throbbing. Next, Leslie took a condom out of the second bedside table drawer, took it out of it's wrapper and rolled it over Sheldon's cock before throwing the wrapper in the trash can. She laid on her back and spread her legs, Sheldon swallowing hard once he saw her bare, cum creamed pussy.

"Enter me", she moaned, her voice making him shiver. He moved towards her and pushed his cock against her entrance. Soon enough, he was inside of her.  
>Sheldon moaned at the feeling of Leslie's warm, wet insides pressed against his cock. He was able to feel it, even through the latex of the condom. Leslie groaned at the feeling of his length inside of her, feeling her clit throbbing as thousands of images and ideas started going through her mind.<p>

"Uhm... what now?", Sheldon asked, sounding confused.

"Just move in and out", Leslie groaned, feeling hot sweat rolling down her thighs.

Sheldon started doing just that. Every move that he would make would increase his newfound feelings of pleasure and arousal. His moaning was becoming louder and heavier with every second. Leslie started running her ass against the bed sheet, trying to find the right position. Soon, she felt Sheldon's cock rubbing against her clit while pressing against her G-spot in the same time. She cried out.

"Am I hurting you?", Sheldon asked, stopping for a moment.

"No", she groaned, desperately trying to stay in that position. "Keep going."

And Sheldon did. Feeling of her hard warm heat was providing him an additional amount of friction to his organ. His whole body felt numb and it felt like every inch of his body was massaged by hot shivers while warm jolt was moving back and forth in his cock.

"Oh... Oh! Yes...", Leslie moaned in mixture of pain and pleasure when Sheldon rubbed his cock against her clit especially hard, arching her back and closing her eyes shut in ecstasy, a single drop of cold sweat rolling down her neck. Her action only made Sheldon want to go faster, and he started doing just that, to both his and Leslie's enjoyment. He even started moaning her name in pleasure while thrusting inside of her, which turned her on so much that she came almost instantly. As he kept moving in and out, Sheldon couldn't keep his eyes off of her breasts, that were moving up and down followed by her heavy breathing . He felt an urge to touch them, feel them. He put both of his hands on her breasts, instantly feeling how soft and warm they are, how hard their nipples are. The feeling was so overwhelming that his eyesight turned blurry for a moment. He started cupping her breasts, going stronger with every second as his arousal increasing, intoxicating smell of Leslie's arousal making him shiver. Feeling of his warm, strong hands cupping her tits turned on Leslie even more: every touch and move that he would make would sent the feeling of heat going up her body and pleasant shivers going down her spine, all the way to her ass. She started sucking on her left index finger, tasting her own juices, every drop sending a warm throbbing feeling down her crotch and shivers down her throat while every move that Sheldon would make would cause her to shiver and cry out in pleasure. All that, combined with what she was already feeling was too much for her. She made it for about two minutes and then she came again, arching her back and crying out Sheldon's name in pleasure, feeling all that feels again, only combined and thousands time more powerful, squeezing his sweaty ass and pulling him in closer in order to make her orgasm all the more intense, her warm wet juices dripping out of her and wrapping around Sheldon's dick. Sight of her body reveling in pleasure and feeling of her warm wet juices wrapping around his penis and her vagina muscles pulsing and rubbing against his length repeatedly, combined with the thrilling sounds of her cries of pleasure-all that was too much for Sheldon and soon enough, he came too, still moving in and out of her furiously, warm jolts running through his body, followed by hot sweat rolling down his back and chest, her eyes still centered on Leslie's naked, flushed body.

Slowly recovering from another orgasm and still surprised by what just took place, Sheldon crawled out of her and laid on the bed, breathing heavily. Noticing that, Leslie moved toward him and carefully slid the condom off his now soft cock, then threw it into a trash can. She also handled him a wet wipe, and he used it to wipe his cock and balls clean and then threw it into a trash can. They were both well spent by then and he didn't turn hard again.

Afterward, Sheldon got dressed and walked toward the bedroom door.

"Well, this was fascinating. I came to touch with another side of myself-the side that I have never encountered before." He stopped for a moment. "It was dirty and wrong and embarrassing thing for me to do, but better that than let that interfere with more important things. Also, it was pleasant, in a physical manner. I can actually see why other people-people not as intelligent as me-can't keep themselves from acting upon them whenever they feel the need too. Luckily, I am not one of them."

He pressed his hand against the door knob and looked at Leslie.

"I will do my best to keep my urges under control from now on, but, due to my eidetic memory, I don't think that will always be possible. So, I expect you to be prepared, but don't expect it to be nothing more than strictly physical relationship." Leslie shivered after hearing him say that, feeling a single drop of cold sweat rolling down the back of her neck.

"I am going to let myself out", he said and left, closing the door behind, leaving Leslie alone with her newfound thoughts and desires.

**A/N: I think that it's possible that Sheldon has urges, only he keeps them strictly under control unless something throws him off guard, which is not easy, but again, all that situation with Leonard and Leslie clearly confused him and Leslie shocked him by correcting his equations so who knows? I usually ship Shamy, but I like Sheldon/Leslie too, and there aren'tt enough fics with that pairing, so I enjoyed writing this. Anyway, thank you for reading and please review!**


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